Rails controller is not called but logger shows “Processing by controller…”

Question

I'm writing a plugin for a Rails application (Discourse) and setup routes like this:

Discourse::Application.routes.append do
  root to: 'custom#show'
end

Unfortunately, the Rails application already defines a series of root routes in its routes.rb file. Since they're specified first, they take precedence according to “Rails Routing from the Outside In: 2.2 CRUD, Verbs, and Actions” .

However, I noticed an odd logger entry when changing the route setup like this:

Discourse::Application.routes.prepend do
  root to: 'custom#show'
end

By using prepend instead of append , Rails' logger output now claims this when requesting the root path / :

INFO -- : Started GET "/" …
INFO -- : Processing by CustomController#show as HTML

However, the action CustomController#show is not actually called. The application behaves exactly as before. How can I get Rails to call this controller and action instead just like the logger claims?

(This is kind of a follow-up question to “For routes with identical URI patterns, which is matched first?” )

Answer 1

Probably some kind of infinite look in your before_action s / ApplicationController / or the inherited Discourse controller.

You can debug it with logging statements and Ctrl-C during the request to see where is the hang (the stacktrace will appear).